The holding pieces or elements for the driven rolls can be supported by pressure plates within the respective windows or openings of the frame members or uprights with intermediate guide pieces being provided as required. The pressure plates can be moved by actuators into the desired positions, and one pressure plate can be provided on each side of the respective roll end.
The adjusting devices are primarily useful when it is desired to change the width or profile of the nip. They are also useful in situations wherein an additional support is to be effected, for working rolls with a rather small diameter, by way of horizontal displacement in reference to the plane in which are positioned the axes of the support rolls. Such a procedure has been described in "Herstellungvon kaltgewalztem Band (Production of Cold-rolled Strip)", Part 1, publisher: Verlag Stahleisen mbh, Duesseldorf, 1970.
The adjusting devices must be of compact and sturdy configuration so as to be easily mounted in the window of an upright of a rolling mill stand.
The devices should also be capable of traversing precisely controllable distances, i.e. distances which can be achieved with simple and reliable means, with the control means being such that they can be operated independently, or synchronized in the same sense or in opposite senses.
Furthermore, purely translatory movements are to be carried out so that the holding elements of the rolls which need to be moved are presented with exactly positioned or aligned support surfaces.
To preclude lengthy control movements, the utilization of gearboxes or gear units has been suggested which are responsive to a rotary control movement. These units provide the respective advance by means of screw spindles and the associated nuts which threadedly engage the screw spindles.
In actual application, however, it was found that such transmissions require a disadvantageously large installation or mounting space.
Accordingly, it is generally not feasible to arrange them within the cylinder block supports which are customarily provided in the respective windows or openings of the base members.
Instead, it was necessary to arrange the piston/cylinder for carrying out the required bending and balancing, or similar control movements, in separate cylinder blocks atop and beneath the gearboxes. Attempts to lower the height of such transmissions were not successful because the requirements for sufficiently large modules and corresponding sufficiently large dimensioned gears and screw spindles could not be satisfied.
Furthermore, subdivision of the cylinder blocks is detrimental because the guide distances for the holding elements, or the pressure pieces which guide them, is limited to an undesirable extent.